test: remove test inter-dependencies

A bunch of tests had interdependencies since we rely on chdir'ing to
tempdirs (and then deleting those dirs) for various tests -- by running
the tests in randomized orders, we'd get randomized failures as it turns
out we were depending on eg. the existence of a previously-generated
.coverage file or being in a still-existing directory.

None of these randomized failures were actual functional issues, but
this should improve the consistency of our test runs in the future.

tests/api/configuration_test.py

@@ -1,6 +1,5 @@
 # pylint: disable=no-self-use
 import os
-import shutil
 import tempfile
 import unittest
 from unittest import mock
@@ -17,17 +16,21 @@
 
 @mock.patch.object(Coveralls, 'config_filename', '.coveralls.mock')
 class Configuration(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.old_cwd = os.getcwd()
+
+    @classmethod
+    def tearDownClass(cls):
+        os.chdir(cls.old_cwd)
+
     def setUp(self):
         self.dir = tempfile.mkdtemp()
-
         os.chdir(self.dir)
         with open('.coveralls.mock', 'w+') as fp:
             fp.write('repo_token: xxx\n')
             fp.write('service_name: jenkins\n')
 
-    def tearDown(self):
-        shutil.rmtree(self.dir)
-
     @pytest.mark.skipif(yaml is None, reason='requires PyYAML')
     @mock.patch.dict(os.environ, {}, clear=True)
     def test_local_with_config(self):

tests/api/encoding_test.py

@@ -1,6 +1,7 @@
 import json
 import os
 import subprocess
+import unittest
 
 from coveralls import Coveralls
 
@@ -9,28 +10,40 @@
 NONUNICODE_DIR = os.path.join(BASE_DIR, 'nonunicode')
 
 
-def test_non_unicode():
-    os.chdir(NONUNICODE_DIR)
-    subprocess.call(['coverage', 'run', 'nonunicode.py'], cwd=NONUNICODE_DIR)
-
-    actual_json = json.dumps(Coveralls(repo_token='xxx').get_coverage())
-    expected_json_part = (
-        '"source": "# coding: iso-8859-15\\n\\n'
-        'def hello():\\n'
-        '    print(\'I like P\\u00f3lya distribution.\')')
-    assert expected_json_part in actual_json
-
-
-def test_malformed_encoding_declaration_py3_or_coverage4():
-    os.chdir(NONUNICODE_DIR)
-    subprocess.call(['coverage', 'run', 'malformed.py'], cwd=NONUNICODE_DIR)
-
-    result = Coveralls(repo_token='xxx').get_coverage()
-    assert len(result) == 1
-
-    assert result[0]['coverage'] == [None, None, 1, 0]
-    assert result[0]['name'] == 'malformed.py'
-    assert result[0]['source'].strip() == ('# -*- cоding: utf-8 -*-\n\n'
-                                           'def hello():\n'
-                                           '    return 1')
-    assert 'branches' not in result[0]
+class EncodingTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.old_cwd = os.getcwd()
+
+    @classmethod
+    def tearDownClass(cls):
+        os.chdir(cls.old_cwd)
+
+    @staticmethod
+    def test_non_unicode():
+        os.chdir(NONUNICODE_DIR)
+        subprocess.call(['coverage', 'run', 'nonunicode.py'],
+                        cwd=NONUNICODE_DIR)
+
+        actual_json = json.dumps(Coveralls(repo_token='xxx').get_coverage())
+        expected_json_part = (
+            '"source": "# coding: iso-8859-15\\n\\n'
+            'def hello():\\n'
+            '    print(\'I like P\\u00f3lya distribution.\')')
+        assert expected_json_part in actual_json
+
+    @staticmethod
+    def test_malformed_encoding_declaration_py3_or_coverage4():
+        os.chdir(NONUNICODE_DIR)
+        subprocess.call(['coverage', 'run', 'malformed.py'],
+                        cwd=NONUNICODE_DIR)
+
+        result = Coveralls(repo_token='xxx').get_coverage()
+        assert len(result) == 1
+
+        assert result[0]['coverage'] == [None, None, 1, 0]
+        assert result[0]['name'] == 'malformed.py'
+        assert result[0]['source'].strip() == ('# -*- cоding: utf-8 -*-\n\n'
+                                               'def hello():\n'
+                                               '    return 1')
+        assert 'branches' not in result[0]

tests/api/reporter_test.py

@@ -18,6 +18,14 @@ def assert_coverage(actual, expected):
 
 
 class ReporterTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.old_cwd = os.getcwd()
+
+    @classmethod
+    def tearDownClass(cls):
+        os.chdir(cls.old_cwd)
+
     def setUp(self):
         os.chdir(EXAMPLE_DIR)
 

tests/git_test.py

@@ -1,7 +1,6 @@
 # pylint: disable=no-self-use
 import os
 import re
-import shutil
 import subprocess
 import tempfile
 import unittest
@@ -18,10 +17,18 @@
 
 
 class GitTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.old_cwd = os.getcwd()
+
+    @classmethod
+    def tearDownClass(cls):
+        os.chdir(cls.old_cwd)
+
     def setUp(self):
         self.dir = tempfile.mkdtemp()
-
         os.chdir(self.dir)
+
         # TODO: switch to pathlib
         open('README', 'a').close()  # pylint: disable=consider-using-with
 
@@ -35,9 +42,6 @@ def setUp(self):
         subprocess.call(['git', 'remote', 'add', GIT_REMOTE, GIT_URL],
                         cwd=self.dir)
 
-    def tearDown(self):
-        shutil.rmtree(self.dir)
-
     @mock.patch.dict(os.environ, {'TRAVIS_BRANCH': 'master'}, clear=True)
     def test_git(self):
         git_info = coveralls.git.git_info()
@@ -74,7 +78,19 @@ def test_gitlog(self):
         assert coveralls.git.gitlog('%s') == GIT_COMMIT_MSG
 
 
-class GitInfoTestEnvVars(unittest.TestCase):
+class GitInfoTest(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.old_cwd = os.getcwd()
+
+    @classmethod
+    def tearDownClass(cls):
+        os.chdir(cls.old_cwd)
+
+    def setUp(self):
+        self.dir = tempfile.mkdtemp()
+        os.chdir(self.dir)
+
     @mock.patch.dict(os.environ, {
         'GIT_ID': '5e837ce92220be64821128a70f6093f836dd2c05',
         'GIT_BRANCH': 'master',
@@ -86,7 +102,7 @@ class GitInfoTestEnvVars(unittest.TestCase):
         'GIT_URL': GIT_URL,
         'GIT_REMOTE': GIT_REMOTE,
     }, clear=True)
-    def test_gitlog_envvars(self):
+    def test_gitinfo_envvars(self):
         git_info = coveralls.git.git_info()
         commit_id = git_info['git']['head'].pop('id')
         assert re.match(r'^[a-f0-9]{40}$', commit_id)
@@ -108,24 +124,14 @@ def test_gitlog_envvars(self):
             },
         }
 
-
-class GitInfoTestNotAGitRepository(unittest.TestCase):
-    def setUp(self):
-        self.dir = tempfile.mkdtemp()
-
-        os.chdir(self.dir)
-
-    def tearDown(self):
-        shutil.rmtree(self.dir)
-
-    def test_gitlog_not_a_git_repo(self):
+    def test_gitinfo_not_a_git_repo(self):
         git_info = coveralls.git.git_info()
 
         self.assertRaises(CoverallsException)
         assert git_info == {}
 
 
-class GitInfoTestBranch(GitTest):
+class GitInfoOverridesTest(unittest.TestCase):
     @mock.patch.dict(os.environ, {
         'GITHUB_ACTIONS': 'true',
         'GITHUB_REF': 'refs/pull/1234/merge',

tests/integration_test.py

@@ -28,6 +28,14 @@ class IntegrationTest(unittest.TestCase):
         'GIT_MESSAGE': 'Ran the integration tests',
     }
 
+    @classmethod
+    def setUpClass(cls):
+        cls.old_cwd = os.getcwd()
+
+    @classmethod
+    def tearDownClass(cls):
+        os.chdir(cls.old_cwd)
+
     def _test_harness(self, num, hits):
         with tempfile.TemporaryDirectory() as tempdir:
             os.chdir(tempdir)